Influences of Multi-Component Supplementary Cementitious Materials on the Performance of Metakaolin Based Geopolymer

Abstract

In this study, the workability and reaction mechanism of metakaolin (MK) based geopolymer blended with rice husk ash (RHA) and silica fume (SF) was investigated. The prepared samples were subjected to tests including compressive strength and fluidity tests. X-ray diffraction (XRD) and Scanning electron microscope (SEM) were employed to explore the phase composition and microstructure of geopolymers. The molecular bonding information of geopolymer was provided by Fourier transform infrared spectroscopy (FTIR). Meanwhile, the porosity of geopolymer was obtained by Mercury intrusion porosimeter (MIP) analysis. The high-activity RHA obtained after calcination at 600°C was used as a supplementary cementitious material to prepare geopolymer. The properties of preventing morphology cracking and compressive strength are improved. The addition of RHA and SF changes the working performance of MK based geopolymer and provided a theoretical basis for future practical applications. Meanwhile, the high chemical activity of SF and RHA contributes to the healing of microcracks.